Abstract
The goal of this paper is to develop a constitutive model for the rapid deformation of clay-rich shear zones. Such a model would be necessary to describe the seismic triggering and evolution of catastrophic landslides. The model is based on: (a) the well-documented in the literature strain-softening and viscoplastic behaviour of saturated clays, and (b) the concept of frictional softening due to heat generated pore-water pressures. The inelastic stress-strain relationship is described with a 1-dimensional cyclic constitutive model of the (Bouc-Wen) type, coupled with a Cam-Clay frictional law with hardening and a set of equations that govern the mechanism of heat-generated pore-water pressure build up. Calibration of the model parameters is accomplished through laboratory tests, with the help of artificial neural network analysis. The influence of key variables on the behaviour of a rapidly deforming shear band is thoroughly investigated and the results of the analysis are critically discussed.
